An active matrix organic EL panel includes a TFT panel incorporated with thin-film transistors (TFTs) for controlling each individual sub-pixel, and organic EL devices disposed over the TFT panel.
Each organic EL device used in organic EL displays generally includes a pixel electrode formed over the surface of the TFT panel; an organic functional layer disposed over the pixel electrode, which organic functional layer contains fluorescent molecules; and a counter electrode disposed over the organic functional layer.
Recent increases in size and definition of organic EL panels has resulted in high probability of generation of defects in which portions of interconnects (e.g., pixel electrodes) on the TFT panel's surface are lost. For improved production yields, various approaches have been proposed that aim to repair such defects generated in the interconnects on the TFT panel (see, e.g., Patent Literatures 1 to 3).
For example, Patent Literature 1 discloses repairing defective interconnects by coating the defect with a conductive repair paste (repair liquid) and baking the same by irradiation with a laser beam. Patent Literature 2 discloses repairing defective interconnects by depositing metal in the defect by irradiation with a laser beam using laser CVD apparatus. Patent Literature 3 discloses repairing defective interconnects by firmly attaching a metal film-bearing transfer member to the defect and irradiating the same with a laser beam to transfer the metallic film into the defect.
Other known approaches include applying a laser beam onto a heat-sensitive layer on the out-coupling side of a defective pixel of an organic EL device to form a light diffusion zone in the heat-sensitive layer, to lessen luminance reduction at the defective pixel (see, e.g., Patent Literatures 4 and 5); detecting, after formation of an organic luminescent layer, a pattern defect in the organic luminescent layer using infrared rays before proceeding to the subsequent step (see, e.g., Patent Literatures 6 and 7); covering the defect in the pixel electrode with insulating material prior to counter electrode formation (see, e.g., Patent Literature 8); cutting, among the multiplicity of interconnection layers stacked on top of each other, only the interconnect in the defective interconnection layer by laser etching based on the stored data such that the defect is electrically separated (see. e.g., Patent Literature 9); configuring organic EL devices to include pixel electrodes disposed on the planarized surface of a TFT panel (see, e.g., Patent Literatures 10 and 11); and configuring organic EL devices to include insulating films between the electrode layers of TFTs for preventing short circuits between the electrodes (see, e.g., Patent Literatures 12 and 13).